Impact of surface steps and oxygen pre-coverage on the adsorption of methylamine on gold

Abstract

Using density functional theory calculations, we report on the adsorption of methylamine on gold and compare its adsorption to a selection of alkylamines, methanol and methanethiol. On the (111) surface, the amines, thiol and alcohol bind in the ontop site with a preference over hollow and bridge sites of 0.3 eV, 0.2 eV and 0.1 eV for methylamine, methanethiol and methanol, respectively. The effect of steps is considered on the (211) surface of gold and we find that methylamine adsorbs 0.2 eV more strongly in the step ontop site of the surface than on the (111) surface. For oxygen atom pre-coverages of 0.04-0.25 ML on the (111) surface, we find cooperative adsorption of amines and oxygen atoms. The energetic costs of adsorbate tilt from the surface normal and of rotation about the gold-heteroatom bond are compared among the studied surfaces and conditions.

Methoxy radical adsorption on gold nanoparticles: a comparison with methanethiol and methylamine radicals

“…In this study, the adsorption is found to be systematically higher on an adatom, in contradiction with the previously mentioned study. Finally, a study addresses on protonated molecules the issue raised in the present one on radicals [36]. Indeed, the authors compare methylamine (NH 2 CH 3 ) adsorption on Au(111) to that of methanol (OHCH 3 ) and methanethiol (SHCH 3 ) and investigate the effect of steps.…”

“…Numerical simulation studies dealing with the adsorption of the methoxy OCH 3 group on gold are also rare. Apart from the above discussed study of Lewoczko et al [36], which focuses on the methanol OHCH 3 molecule and concludes that it has the smallest adsorption energy and the greatest distance from the gold surface when compared with methylamine and methanethiol, two other studies can be mentioned. In the first one, simulations of methoxy adsorption on transition metal surfaces describe the most favorable adsorption site as the H f cc one on Au(111) [38].…”